<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta http-equiv="X-UA-Compatible" content="ie=edge" />
    <title>Document</title>
  </head>

  <body>
    <div id="app"></div>
    <script>
      // {
      //   //var a = "测试"
      //   let b = "测试2"
      //   let b = "测试"
      //   console.log(b);
      // }

      {
        let a = "测试"
        function fn() {
          console.log(a)
        }
        fn()
      }
    </script>
  </body>
</html>
